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On Wednesday, July 6, the World Health Organisation (WHO) confirmed that a new sub-lineage of the COVID-19-causing coronavirus’ Omicron variant, widely referred to as BA.2.75, has been detected in India and at least ten other countries.

This update arrived just days after an Israeli expert, Dr Shay Fleishon with the Central Virology Laboratory at Sheba Medical Center in Tel Hashomer, revealed that 85 sequences of this new sub-lineage had been uploaded from different countries on Nextstrain, an open-source platform of genomic data.

Of these uploads, 69 were from India (as of Sunday, July 3): Delhi (1), Haryana (6), Himachal Pradesh (3), Jammu (1), Karnataka (10), Madhya Pradesh (5), Maharashtra (27), Telangana (2), Uttar Pradesh (1) and West Bengal (13). And besides India, the strain has also been reported by Japan (1), Germany (2), the UK (6), Canada (2), the US (2), Australia (1) and New Zealand (2).

While it’s still “too soon to tell” whether BA.2.75 will be the next dominant variant, Dr Fleishon noted that the sub-variant could be “alarming because it may imply a trend to come”.

Furthermore, the Bloom Lab at the Fred Hutch research institute in the US also described this sub-variant as “worth tracking, as it has appreciable antigenic change relative to its parent BA.2”.

But what exactly is the BA.2.75, and what do we know about it so far? Listed below are answers to some related FAQs.

What is the BA.2.75 sub-lineage of the Omicron variant?

By now, we know that the Omicron variant comprises several lineages, viz. BA.1, BA.2, BA.3, BA.4, and BA.5. At present, the BA.2 Omicron lineage seems to have replaced the BA.1 lineage as the predominant circulating variant of concern of SARS-CoV-2 around the world. In Europe and America, BA.4 and BA.5 continue to drive COVID waves.

In recent months, however, several second-generation variants based on the aforementioned Omicron lineages have originated worldwide, each possessing its own set of distinct mutations. The BA.2.75 sub-lineage is one such second-gen variant of its parent lineage, the BA.2.

Is BA.2.75 more transmissible?

It’s possible. While the sequences available to analyse this subvariant are still limited, it does seem to have some mutations on the receptor bindings of its spike protein — a part that’s key for the virus to attach itself to the human receptor.

Another fact that adds to this high transmissibility hypothesis is that the BA.2.75 is the only second-generation variant of the Omicron that has managed to spread across multiple states and even countries. Prior to this one, all the other second-generation variants have only been found in a few cases within one region.

However, nothing is known for sure just yet, and more sequences will have to be analysed before we can arrive at a concrete conclusion.

Does BA.2.75 cause more severe infections?

We do not know. The WHO is currently tracking whether this subvariant has properties of being more clinically severe or immunity-invasive.

But so far, this lineage has not been documented to have enhanced severity or disease spread, according to sources close to the Indian central government.

Here’s what WHO chief scientist Soumya Swaminathan recently said about the BA.2.75:

What is being done to deal with the potential threat of BA.2.75?

Officials of the central government have indicated that they will continue to closely monitor the spread of this sub-lineage as well as any other emerging sub-lineages of Omicron across India.

WHO Director-General Tedros Adhanom Ghebreyesus has also stated that the UN body and the TAG VE (Technical Advisory Group on Virus Evolution) will continue to carry out similar procedures in India and around the world.

What can we do to protect ourselves from the potential threat of BA.2.75?

To keep safe from this or any other variant, ensure you have received the first two as well as the booster doses of the COVID-19 vaccine. Moreover, it is crucial to continue wearing masks and following COVID-appropriate behaviour at all times, especially when outdoors and in crowded environments. Constant vigilance is key.


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